The ASTM A735 standard covers low-carbon nickel-chromium-molybdenum alloy steel plates, and their surface quality requirements generally include the following:
1. The surface should be smooth without obvious bulges, depressions or defects.
2. There should be no obvious oxide layer, rust spots or other signs of corrosion.
3. The surface should be clean and free of oil stains, dust or other contaminants.
4. The surface may require specific treatment, such as rust removal, shot blasting, etc., to ensure compliance with standard requirements.
The heat treatment requirements specified in the ASTM A735 standard generally involve the following aspects:
1. Heating temperature and holding time: Specify the heating temperature that the steel needs to reach during heat treatment, and the length of time that needs to be kept at that temperature.
2. Cooling method: It stipulates how steel should be cooled after heat treatment, including air cooling, oil quenching, water quenching and other different cooling methods.
3. Annealing: Annealing may be required to eliminate internal stress, increase toughness, or improve processing properties.
4. Normalizing treatment: For some specific performance requirements, normalizing treatment may be required to adjust the structure and hardness of the steel.
5. Quenching treatment: In some cases, steel needs to be quenched to achieve higher hardness and strength.
6. Performance test after heat treatment: Specifies the performance test standards and related requirements that need to be carried out after heat treatment.
The above are general steel heat treatment requirements that may be included in the ASTM A735 standard. Specific requirements will vary depending on the type, composition and use of the steel, and it is recommended to consult the latest version of the ASTM A735 standard document for detailed and accurate information. Specific surface quality requirements should be referenced to the relevant sections of the ASTM A735 standard and consultation between the customer and manufacturer.
